27 J pinion shaft bush/sprocket shaft outer race removal

[Martin Pettingell]

I need to remove the brass pinion shaft bush and the sprocket shaft outer race from the crank cases of my 27 J

It looks as though the pinion bush could just knock out with a little gentle persuasion. I plan on using an old piston or similar underneath just to give the case some support

The sprocket bearing race though appears to be accessed by 4 holes on the outer side of the case. I imagine HD would have produced a special 4 pronged punch tool to assist in getting this out square and without damaging the case.

I suspect these are parts often replaced and I'm thinking there must be some experience of doing it out there. I have had a search though and could not find a post on the subject - sorry if it missed it and its been covered before.

Any tips please and how to approach this - what to do / not to do - and in particular how to get the outer race out. Should I try and fabricate some kind of 4 pronged punch? or is there a technique for this or something on the market that will do the job?

Thanks

Martin

[Steve Swan]

The drive shaft steel race removed without difficulty in my case. I used a torch with MAPP gas to heat the area around the race, supporting the area of the case the race is in, and using a small punch to fit through the 4 holes rotated my way around the holes with hammer and punch. The race readily responded to this approach.

[Martin Pettingell]

Thanks Steve. On the inside of my case there looks to be a grub screw or something similar at about 11 o’clock when the engine is upright. I wondered whether this needs to be removed before attempting to press out the race. There is nothing in the 1918 repair manual that I am looking at but maybe this was a later addition.
While on the issue how did you manage to line up the cases after the new bushes/ bearing was fitted?
Thanks
Martin

[Steve Swan]

Thanks Steve. On the inside of my case there looks to be a grub screw or something similar at about 11 o’clock when the engine is upright. I wondered whether this needs to be removed before attempting to press out the race. There is nothing in the 1918 repair manual that I am looking at but maybe this was a later addition.
While on the issue how did you manage to line up the cases after the new bushes/ bearing was fitted?
Thanks
Martin

Martin, i don't recall a grub screw in the drive bushing area. if you are referring to the bronze pinion bushing, i seem to remember relief cut in the periphery of the bushing that a pin inserted into the RH case. attached is pic of inside of my LH case. unfortunately, i do not have a pic of inside my RH case.

i sent my entire lower end assembly to a specialist, Truett & Osborn, in Witchita, Kansas. My cases are not matching, and of course had new drive/pinion bushings installed as well as soem pretty major weld repairs to the double V crack extending from the two rear mount holes into the belly of the case. all things considered, i figured sending it off my best option, and since i don't have equipment to line bore the holes or true flywheels.

20160119_115113.jpg

[Jerry Wieland]

I am not familiar with the term 'grub screw' but it is not uncommon to see a set type screw added to help
anchor the bushing in place. The factory started it in about 1952 I believe and offered a retro fit in the Shop-Dope.

Jerry

[Rubone]

I am not familiar with the term 'grub screw' but it is not uncommon to see a set type screw added to help
anchor the bushing in place. The factory started it in about 1952 I believe and offered a retro fit in the Shop-Dope.

Jerry,
Grub screw is common Brit or Commonwealth English term for a set screw.

[Martin Pettingell]

Thanks Guys.

I guess my case has had the set screw added at some point in its history. As Rubone mentions we call 'em grub screws in the UK but its the same thing. It will have to come out before I can get the race out.

Regards

Martin

[MMasa]

1929 JD left cases had 3 factory installed set screws on the case race.
Mark